Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 3.641
Filter
1.
World J Radiol ; 16(6): 168-183, 2024 Jun 28.
Article in English | MEDLINE | ID: mdl-38983842

ABSTRACT

Contrast-induced acute kidney injury (CI-AKI) is the third leading cause of acute kidney injury deriving from the intravascular administration of contrast media in diagnostic and therapeutic procedures and leading to longer in-hospital stay and increased short and long-term mortality. Its pathophysiology, although not well-established, revolves around medullary hypoxia paired with the direct toxicity of the substance to the kidney. Critically ill patients, as well as those with pre-existing renal disease and cardiovascular comorbidities, are more susceptible to CI-AKI. Despite the continuous research in the field of CI-AKI prevention, clinical practice is based mostly on periprocedural hydration. In this review, all the investigated methods of prevention are presented, with an emphasis on the latest evidence regarding the potential of RenalGuard and contrast removal systems for CI-AKI prevention in high-risk individuals.

2.
Ultrasonics ; 142: 107397, 2024 Jul 03.
Article in English | MEDLINE | ID: mdl-38986247

ABSTRACT

Monitoring the microstructural change in cementitious materials during hydration is an essential but challenging task. Therefore, a non-invasive and sophisticated technique is warranted to understand the microscopic behaviour of the multiphase cementitious materials (where the length scale of the constituents varies from centimeters to micrometers) in different stages of hydration. Due to exothermic hydration reactions, different hydration products start to evolve with individual mechanical properties. In concrete, an interface transition zone (ITZ) appears between the aggregate surface and paste matrix, which influences the overall properties of concrete material. In the present research, 1) several wave characteristics, such as wave velocity, energy distribution, and signal phase are found out using Ultrasonic Pulse Velocity (UPV), Wavelet Packet Energy (WPE) and Hilbert Transform (HT) methods, to monitor the hydration mechanism (1d-28d) in cement-based materials with two levels of heterogeneities (cement paste and concrete, representing microscale and mesoscale, respectively). Also, the unique nonlinear behaviour is studied in the frequency domain using the promising Sideband Energy Ratio (SER) and Sideband Peak Count Index (SPC-I) methods. 2) Numerical simulations are carried out to understand the wave interaction in the developing microstructure. A discretized microstructure of cement shows microscopic details of each phase at any instant of hydration (e.g., formation stage and after complete maturity level). The experimental and numerical investigations on the characteristics of the nonlinear ultrasonic wave propagation show the impact of microstructural development of multi-scale cementitious materials during hydration.

3.
Skin Res Technol ; 30(7): e13849, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38978227

ABSTRACT

BACKGROUND: Skin hydration (SKH) measurements are used for multiple purposes: to study skin physiology, to clinically investigate dermatological issues, and to assess localized skin water in pathologies like diabetes and lymphedema. Often the volar forearm is measured at various times of day (TOD). This report aims to characterize intra-day variations in volar forearm SKH to provide guidance on expected TOD dependence. MATERIALS AND METHODS: Forty medical students (20 male) self-measured tissue dielectric constant (TDC) on their non-dominant forearm in triplicate as an index of local skin tissue water every 2 h starting at 0800 and ending at 2400 h. All were trained and pre-certified in the procedure and had whole-body fat (FAT%) and water (H2O%) measured. Day average TDC (TDCAVG) was determined as the average of all time points expressed as mean ± SD. RESULTS: Males versus females had similar ages (25.1 ± 2.2 years vs. 25.1 ± 1.5 years), higher H2O% (56.6 ± 5.0 vs. 51.8 ± 5.7, p = 0.002), and higher TDCAVG (32.7 ± 4.1 vs. 28.5 ± 5.1, p = 0.008). TDC values were not significantly impacted by H2O% or FAT%. Female TDC exhibited a significant decreasing trend from morning to night (p = 0.004); male TDC showed no trend. CONCLUSION: Skin water assessed by TDC shows some intra-day variations for females and males but with quite different temporal patterns. Clinical relevance relates to the confidence level associated with skin hydration estimates when measured at different times of day during normal clinic hours which, based on the present data, is expected to be around 5% for both males and females.


Subject(s)
Body Water , Forearm , Humans , Male , Female , Adult , Skin , Young Adult , Skin Physiological Phenomena
4.
Emerg Nurse ; 2024 Jul 09.
Article in English | MEDLINE | ID: mdl-38978385

ABSTRACT

This article examines the role of water in the body, the balance of fluids in the body and the provision of intravenous (IV) fluids to patients who are dehydrated, providing a comprehensive overview of these topics for nurses. The author details various aspects of practice in IV fluid therapy, including the types of fluids used, their indications, administration and potential side effects. The article also discusses dehydration and how nurses can identify and treat this complication, which can occur as a result of many different conditions. Drawing on the relevant research, this article aims to advance nurses' knowledge of the care of patients who are dehydrated and require IV fluid therapy.

5.
Des Monomers Polym ; 27(1): 51-61, 2024.
Article in English | MEDLINE | ID: mdl-38979124

ABSTRACT

To explore the effect of polycarboxylate superplasticizers on the strength and hydration performance of alkali slag building materials, this study prepared cross-linked polycarboxylate superplasticizers with different ratios of hydrogen peroxide, methyl allyl alcohol polyoxyethylene ether, acrylic acid, polyethylene glycol diacrylate, monomer aqueous solution, reducing agent, chain transfer agent, etc. according to certain ratios, and tested their effects on the hydration performance and strength of alkali slag building materials. Through experimental analysis, it was found that the higher the proportion of cross-linked polycarboxylate based high-efficiency water-reducing agents, the lower the initial flowability of building material slurry; The addition of cross-linked polycarboxylate water-reducing agent will prolong the initial and final setting time of alkali slag building materials, delaying the hydration time of building materials; Cross linked polycarboxylate superplasticizers can reduce the electrical conductivity of alkali slag building material slurry, delaying its hydration rate; Different ratios of water-reducing agents have a significant impact on the water reduction rate of alkali slag building materials, with V2 water-reducing agent having the highest water-reduction rate of 28.6%; Cross linked polycarboxylate superplasticizers can increase the flexural and compressive strength of alkali slag building materials. Therefore, cross-linked polycarboxylate water-reducing agents have shown great potential in regulating the properties of alkali slag building materials.

6.
Int J Biol Macromol ; : 133713, 2024 Jul 08.
Article in English | MEDLINE | ID: mdl-38986993

ABSTRACT

This article describes the molecular mechanism by which tetraalkylammonium chloride ([R4N]Cl: R- = methyl (Me), ethyl (Et), propyl (Pr),butyl (Bu)) modulates the stability, folding, and dynamics of cytochrome c (Cyt c). Analysis of [R4N] Cl effects on thermal/chemical denaturations, millisecond refolding/unfolding kinetics, and slow CO-association kinetics of Cyt c without and with denaturant providing some significant results: (i) [R4N]Cl decreasing the unfolding free energy estimated by thermodynamic and kinetic analysis of thermal/chemical denaturation curves and kinetic chevrons (Log kobs-[GdmCl]) of Cyt c, respectively (ii) hydrophobicity of R-group of [R4N]Cl, preferential inclusion of [R4N]Cl at the protein surface, and destabilizing enthalpic attractive interactions of [Me4N]Cl and steric entropic interactions of [Et4N]Cl,[Pr4N]Cl and [Bu4N]Cl with protein contribute to [R4N]Cl-induced decrease thermodynamic stability of Cyt c (iii) [R4N]Cl exhibits an additive effect with denaturant to decrease thermodynamic stability and refolding rates of Cyt c (iv) low concentrations of [R4N]Cl (≤ 0.5 M) constrain the motional dynamics while the higher concentrations (>0.75 M [R4N]Cl) enhance the structural-fluctuations that denture protein (v) hydrophobicity of R-group of [R4N]Cl alters the [denaturant]-dependent conformational stability, refolding-unfolding kinetics, and CO-association kinetics of Cyt c. Furthermore, the MD simulations depicted that the addition of 1.0 M of [R4N]Cl increased the conformational fluctuations in Cyt c leading to decreased structural stability in the order [Me4N]Cl < [Et4N]Cl < [Pr4N]Cl < [Bu4N]Cl consistent with the experimental results.

7.
J Colloid Interface Sci ; 675: 451-460, 2024 Jul 06.
Article in English | MEDLINE | ID: mdl-38981254

ABSTRACT

HYPOTHESIS: Ice friction plays a crucial role in both basic study and practical use. Various strategies for controlling ice friction have been developed. However, one unsolved puzzle regarding ice friction is the effect of ion-ice interplay on its tribological properties. EXPERIMENTS AND SIMULATIONS: Here, we conducted ice friction experiments and summarized the specific effects of hydrated ions on ice friction. By selecting cations and anions, the coefficient of ice friction can be reduced by more than 70 percent. Experimental spectra, low-field nuclear magnetic resonance (LF-NMR), density functional theory (DFT) calculations, and Molecular dynamics (MD) simulations demonstrated that the addition of ions could break the H-bonds in water. FINDINGS: The link between the charge density of ions and the coefficients of ice friction was revealed. A part of the ice structure was changed from an ice-like to a liquid-like interfacial water structure with the addition of ions. Lower charge density ions led to weaker ionic forces with the water molecules in the immobilized water layer, resulting in free water molecules increasing in the lubricating layer. This study provides guidance for preparing ice-making solutions with low friction coefficients and a fuller understanding of the interfacial water structure at low temperatures.

8.
IUCrJ ; 2024 Sep 01.
Article in English | MEDLINE | ID: mdl-38989800

ABSTRACT

Stimulated by informal conversations at the XVII International Small Angle Scattering (SAS) conference (Traverse City, 2017), an international team of experts undertook a round-robin exercise to produce a large dataset from proteins under standard solution conditions. These data were used to generate consensus SAS profiles for xylose isomerase, urate oxidase, xylanase, lysozyme and ribonuclease A. Here, we apply a new protocol using maximum likelihood with a larger number of the contributed datasets to generate improved consensus profiles. We investigate the fits of these profiles to predicted profiles from atomic coordinates that incorporate different models to account for the contribution to the scattering of water molecules of hydration surrounding proteins in solution. Programs using an implicit, shell-type hydration layer generally optimize fits to experimental data with the aid of two parameters that adjust the volume of the bulk solvent excluded by the protein and the contrast of the hydration layer. For these models, we found the error-weighted residual differences between the model and the experiment generally reflected the subsidiary maxima and minima in the consensus profiles that are determined by the size of the protein plus the hydration layer. By comparison, all-atom solute and solvent molecular dynamics (MD) simulations are without the benefit of adjustable parameters and, nonetheless, they yielded at least equally good fits with residual differences that are less reflective of the structure in the consensus profile. Further, where MD simulations accounted for the precise solvent composition of the experiment, specifically the inclusion of ions, the modelled radius of gyration values were significantly closer to the experiment. The power of adjustable parameters to mask real differences between a model and the structure present in solution is demonstrated by the results for the conformationally dynamic ribonuclease A and calculations with pseudo-experimental data. This study shows that, while methods invoking an implicit hydration layer have the unequivocal advantage of speed, care is needed to understand the influence of the adjustable parameters. All-atom solute and solvent MD simulations are slower but are less susceptible to false positives, and can account for thermal fluctuations in atomic positions, and more accurately represent the water molecules of hydration that contribute to the scattering profile.

9.
Curr Nutr Rep ; 2024 Jul 12.
Article in English | MEDLINE | ID: mdl-38995600

ABSTRACT

PURPOSE OF REVIEW: Climate change is predicted to increase the frequency and severity of exposure to hot environments. This can impair health, physical performance, and productivity for active individuals in occupational and athletic settings. This review summarizes current knowledge and recent advancements in nutritional strategies to minimize the impact of exertional-heat stress (EHS). RECENT FINDINGS: Hydration strategies limiting body mass loss to < 3% during EHS are performance-beneficial in weight-supported activities, although evidence regarding smaller fluid deficits (< 2% body mass loss) and weight-dependent activities is less clear due to a lack of well-designed studies with adequate blinding. Sodium replacement requirements during EHS depends on both sweat losses and the extent of fluid replacement, with quantified sodium replacement only necessary once fluid replacement > 60-80% of losses. Ice ingestion lowers core temperature and may improve thermal comfort and performance outcomes when consumed before, but less so during activity. Prevention and management of gastrointestinal disturbances during EHS should focus on high carbohydrate but low FODMAP availability before and during exercise, frequent provision of carbohydrate and/or protein during exercise, adequate hydration, and body temperature regulation. Evidence for these approaches is lacking in occupational settings. Acute kidney injury is a potential concern resulting from inadequate fluid replacement during and post-EHS, and emerging evidence suggests that repeated exposures may increase the risk of developing chronic kidney disease. Nutritional strategies can help regulate hydration, body temperature, and gastrointestinal status during EHS. Doing so minimizes the impact of EHS on health and safety and optimizes productivity and performance outcomes on a warming planet.

10.
J Pediatr Urol ; 2024 Jun 27.
Article in English | MEDLINE | ID: mdl-38991880

ABSTRACT

AIMS: To determine the level of agreement between healthcare professionals, patients and their parents/guardians in the interpretation of the urine color scale (UCS) in cases of urinary dysfunction, analyzing the applicability of the scale as a diagnostic tool determining the hydration status. METHODS: This was a cross-sectional study involving 5-17-year-old patients with lower urinary tract symptoms (LUTS) and enuresis. The study was conducted in a public healthcare referral center for pediatric urology in the Brazilian state of Bahia between October 2019 and March 2020. The Kolmogorov-Smirnov test was used to assess the distribution of the variables. Agreement was assessed using the kappa coefficient and weighted kappa. The z-test was used to determine significant differences between the kappa and weighted kappa. The statistical analysis was conducted using SPSS, version 14, and significance was established at p < 0.05. RESULTS: Forty-four patients were included. The kappa value was 32.4% (p = 0.000) for the agreement between healthcare professionals and patients, 41.9% (p = 0.000) for agreement between healthcare professionals and parents/guardians, and 25.0% (p = 0.001) for agreement between patients and parents/guardians. The weighted kappa was 70.6% (p = 0.000) for agreement between healthcare professionals and patients, 82.4% (p = 0.000) for agreement between healthcare professionals and parents/guardians, and 51.5% (p = 0.001) for agreement between patients and parents/guardians. There was a statistically significant difference in kappa values when the healthcare professionals were compared with the other groups. CONCLUSIONS: Although there were some inconsistencies in interpretation, the UCS proved to be a useful tool with which to evaluate patients' hydration status.

11.
Br J Nurs ; 33(13): S14-S24, 2024 Jul 04.
Article in English | MEDLINE | ID: mdl-38954455

ABSTRACT

Clinically assisted nutrition and hydration (CANH) decision-making in adult patients presents complex ethical dilemmas that require careful consideration and navigation. This clinical review addresses the multifaceted aspects of CANH, emphasising the importance of ethical frameworks and the role of advanced clinical practitioners (ACPs) in guiding decision-making processes. The pivotal role of ACPs is highlighted, from their responsibilities and challenges in decision-making to the collaborative approach they facilitate involving patients, families and multidisciplinary teams. The article also explores ethical principles such as autonomy, beneficence, non-maleficence, and justice, elucidating their application in CANH decision-making. Legal and ethical frameworks covering CANH are examined, alongside case studies illustrating ethical dilemmas and resolutions. Patient-centred approaches to CANH decision-making are discussed, emphasising effective communication and consideration of cultural and religious beliefs. End-of-life considerations and palliative care in CANH are also examined, including the transition to palliative care and ethical considerations in withdrawal or withholding of CANH. Future directions for research and implications for clinical practice are outlined, highlighting the need for ongoing ethical reflection and the integration of ACPs in CANH decision-making.


Subject(s)
Fluid Therapy , Humans , Fluid Therapy/ethics , Adult , Decision Making/ethics , Nutritional Support/ethics , Terminal Care/ethics , Palliative Care/ethics
12.
Curr Res Food Sci ; 8: 100780, 2024.
Article in English | MEDLINE | ID: mdl-38957286

ABSTRACT

Sorghum starch granules are encapsulated in a rigid protein matrix that prevents the granules from fully swelling and gelatinizing. Sprouting and subsequent drying treatment can affect the gelatinization properties of sorghum starch. This study aimed to evaluate the gelatinization properties of flours from unsprouted (US) and sprouted (S50, S40) sorghum dried at 50 °C (6h) and 40 °C (12h), respectively. Swelling power (Sp), thermal properties (DSC) and 1H molecular mobility and dynamics were evaluated at different water contents (38-91%). Sp increased with increasing water content, with S40 showing the lowest values, probably due to prolonged amylase activity and thus starch breakdown. Sprouting increased gelatinization temperatures; however, these differences disappeared for high water contents (82 and 91%). From a molecular point of view, sprouted samples showed a decrease in protons associated to the rigid protein matrix and starch structures. 1H CPMG results showed the presence of 4 populations at 38% water content. The evolution of the more mobile population with increasing water content supported the assignment of more mobile water fraction to this population. Sprouting decreased the mobility of populations in unheated samples, suggesting an increase in molecular bonds between flour biopolymers and water. After heating, however, increased molecular mobility in S40 indicated the formation of a weaker network between starch, protein, and water at the molecular level. These results suggest that post-sprouting drying treatment influences sorghum gelatinization, with potential modulation by water content. This study contributes to understanding the application of sprouted sorghum in foods with different moisture content.

13.
J Voice ; 2024 Jul 06.
Article in English | MEDLINE | ID: mdl-38972776

ABSTRACT

PURPOSE: The primary goal of this investigation was to characterize the effect of the first-generation, over-the-counter antihistamine Chlor-Trimeton on laryngeal structure and function in a previously unstudied population - individuals diagnosed with allergic rhinitis who routinely take over-the-counter antihistamines and deny the experience or diagnosis of voice disorder. STUDY DESIGN: Prospective within-participant multimodality repeated measures design. METHODS: Eight consented participants (seven females, one male) previously diagnosed with allergic rhinitis and without history of voice disorder who routinely took over-the-counter antihistamines completed the study. Volunteers completed the following measures before and 2hours after antihistamine administration: perceptual vocal function measures, phonation threshold pressure (PTP), acoustic measures, and laryngeal imaging. All pre- and post-administration data were descriptively analyzed for clinically significant change. RESULTS: No clinically significant differences were identified for any acoustic or aerodynamic measures taken. Analyses of laryngeal imaging data indicated that all participants had evidence of mucosal changes in one or more of the following parameters: increased vascularity, mucus in the anterior commissure, and vocal fold color changes, all of which are consistent with prior descriptions of allergy larynx. CONCLUSIONS: Empirical study of laryngeal appearance in individuals diagnosed with allergic rhinitis, affirmed clinical observations of laryngeal tissue changes consistent with allergy larynx. Stable PTP suggests potential vocal fold cover adaptations from routine use of over-the-counter antihistamines that may buffer the typical desiccating effect on voice function observed in prior studies of healthy individuals.

14.
J Mol Model ; 30(8): 253, 2024 Jul 06.
Article in English | MEDLINE | ID: mdl-38970670

ABSTRACT

CONTEXT: Carbonyl compounds, especially aldehydes, emitted to the atmosphere, may suffer hydration in aerosols or water droplets in clouds. At the same time, they can react with hydroxyl radicals which may add or abstract hydrogen atoms from these species. The interplay between hydration and hydrogen abstraction is studied using density functional and quantum composite theoretical methods, both in the gas phase and in simulated bulk water. The H-abstraction from the aldehydic and geminal diol forms of formaldehyde, acetaldehyde, glycolaldehyde, glyoxal, methylglyoxal, and acrolein is studied to determine whether the substituent has any noticeable effect in the preference for the abstraction of one form or another. It is found that abstraction of the H-atom adjacent to the carbonyl group gives a more stable radical than same abstraction from the geminal diol in the case of formaldehyde, acetaldehyde, and glycolaldehyde. The presence of a delocalizing group in the Cα (a carbonyl group in glyoxal and methylglyoxal, and a vinyl group in acrolein), reverts this trend, and now the abstraction of the H-atom from the geminal diol gives more stable radicals. A further study was conducted abstracting hydrogen atoms from the other different positions in the species considered, both in the aldehydic and geminal diol forms. Only in the case of glycolaldehyde, the radical formed by H-abstraction from the -CH2OH group is more stable than any of the other radical species. Abstraction of the hydrogen atom in one of the hydroxyl groups in the geminal diol is equivalent to the addition of the •OH radical to the aldehyde. It leads, in some cases, to decomposition into a smaller radical and a neutral molecule. In these cases, some interesting theoretical differences are observed between the results in gas phase and (simulated) bulk solvent, as well as with respect to the method of calculation chosen. METHODS: DFT (M06-2X, B2PLYP, PW6B95), CCSD(T), and composite (CBS-QB3, jun-ChS, SCVECV-f12) methods using Dunning basis sets and extrapolation to the CBS limit were used to study the energetics of closed shell aldehydes in their keto and geminal-diol forms, as well as the radical derived from them by hydrogen abstraction. Both gas phase and simulated bulk solvent calculations were performed, in the last case using the Polarizable Continuum Model.

15.
Methods Enzymol ; 700: 105-126, 2024.
Article in English | MEDLINE | ID: mdl-38971597

ABSTRACT

Hyperspectral imaging is a technique that captures a three-dimensional array of spectral information at each spatial location within a sample, enabling precise characterization and discrimination of biological structures, materials, and chemicals, based on their unique spectral features. Nowadays most commercially available confocal microscopes allow hyperspectral imaging measurements, providing a valuable source of spatially resolved spectroscopic data. Spectral phasor analysis quantitatively and graphically transforms the fluorescence spectra at each pixel of a hyperspectral image into points in a polar plot, offering a visual representation of the spectral characteristics of fluorophores within the sample. Combining the use of environmentally sensitive dyes with phasor analysis of hyperspectral images provides a powerful tool for measuring small changes in lateral membrane heterogeneity. Here, we focus on applications of spectral phasor analysis for the probe LAURDAN on model membranes to resolve packing and hydration. The method is broadly applicable to other dyes and to complex systems such as cell membranes.


Subject(s)
Fluorescent Dyes , Spectrometry, Fluorescence , Fluorescent Dyes/chemistry , Spectrometry, Fluorescence/methods , Microscopy, Confocal/methods , Laurates/chemistry , Cell Membrane/chemistry , Cell Membrane/metabolism , 2-Naphthylamine/analogs & derivatives , 2-Naphthylamine/chemistry , Lipid Bilayers/chemistry
16.
Materials (Basel) ; 17(11)2024 May 31.
Article in English | MEDLINE | ID: mdl-38893922

ABSTRACT

In this research, the properties and cementitious performance of thermally activated cement pastes (referred to as DCPs) are investigated. Hydrated pastes prepared from Portland cement and slag blended cement were subjected to different thermal treatments: 350 °C for 2 h, 550 °C for 2 h, 550 °C for 24 h and 750 °C for 2 h. The properties and the reactivity as SCM of the DCPs were characterised as well as their effect on the mechanical performance and hydration of new blended cements incorporating the DCPs as supplementary cementitious materials (SCMs). It was observed that the temperature and duration of the thermal treatment increased the grindability and BET specific surface area of the DCP, as well as the formation of C2S phases and the reactivity as SCM. In contrast, the mechanical strength results for the blended cements indicated that thermal treatment at 350 °C for 2 h provided better performance. The hydration study results showed that highly reactive DCP interfered with the early hydration of the main clinker phases in Portland cement, leading to early setting and slow strength gain. The effect on blended cement hydration was most marked for binary Portland cement-DCP blends. In contrast, in the case of ternary slag cement-DCP blends the use of reactive DCP as SCM enabled to significantly increase early age strength.

17.
Materials (Basel) ; 17(11)2024 Jun 06.
Article in English | MEDLINE | ID: mdl-38894034

ABSTRACT

Although quartz powder is a common concrete filling material, the importance and originality of this study lies in the development of a hydration model for quartz powder-cement binary mixtures and the adoption of this model to predict the development of concrete material properties. The purpose of this study is to use this model to promote the material design of environmentally friendly concrete and to elucidate the relationships in the development of the various properties of quartz powder concrete. The method used in this study was as follows: The parameters of the hydration model were obtained through seven days of hydration heat experiments. The hydration heat up to 28 days was also calculated, and the various properties of the concrete were predicted from the heat of hydration. The main findings of this study were as follows: (1) The ultimate hydration heat released per gram of cement for the different quartz powder substitution rates and quartz powder particle fineness was the same, at 390.145 J/g cement, as was the shape index of the hydration model at -1.003. (2) Moreover, through the model calculations, we found that, at the twenty-eighth day of the curing period for the quartz powder specimens with different quartz powder substitution amounts and different fineness, the reaction level of the cement was similar, at 0.963, as were the values of the cumulative heat of hydration, with both at 375.5 J/g cement. (3) The model showed that, in the late stage (28 days) of hydration for quartz powders of different fineness and when the substitution amount was the same, the cumulative heat of hydration over 28 days was similar. (4) The properties of concrete were evaluated using the calculated hydration heat. Overall, the predictive performance of the power and linear functions was similar, with no significant differences being found.

18.
Healthcare (Basel) ; 12(11)2024 Jun 06.
Article in English | MEDLINE | ID: mdl-38891227

ABSTRACT

It is known that the quantity, makeup, and distribution of bodily fluids have a significant impact on the cognitive health, physiological health, and cell activity of human beings. This narrative could be influenced by the level of knowledge about hydration, dehydration, and the practice of Adequate Water Intake (AWI) of an individual based on the recommended daily Total Water Intake (TWI) by either the World Health Organization (WHO) or the European Food Safety Authority (EFSA). In this study, we have developed and validated a scale to adequately measure knowledge of the recommended daily Total Water Intake (TWI) practices among foreign students at Óbuda University, Hungary. Hence, we implemented an 11-item scale to measure the Knowledge of Hydration (KH-11) and evaluate its psychometric properties among students. This study is an online cross-sectional study assessing water intake knowledge with the use of the KH-11 tool among 323 students with ages ranging from 18 to 35 years, who have enrolled for at least two semesters at the University. The statistical analysis performed was reliability (using Cronbach alpha ≥ 70%) and factor analysis. Knowledge levels were categorized as poor (<50%), intermediate (50-70%), or adequate (71-100%). The intraclass correlation, chi-square, and rotated component matrix were also estimated and reported. Data were analyzed using SPSS version 25. Cronbach's alpha analysis revealed that the KH-11 had an overall good reliability with a value of 0.80, where the survey items had an acceptable level of consistency ranging from 0.75 to 0.81 and demonstrated sufficient independence from each other as Pearson's R within factors was positive and ranged from 0.02 to 0.74. In evaluating the participants' knowledge of hydration, the total possible score for the scale is 72, while the mean score for the KH-11 was 55.2 ± 11.61 SD, and the factor analysis model yielded an acceptable fit (χ2 = 3259.4, p = 0.000). We recorded a high-level positive concordance of 0.770 with an average intraclass correlation of 0.80 at a 95% CI, where p-value = 0.000. Our findings show that the majority (66.3%) of the students have a good knowledge of hydration. However, the skewed distribution of the knowledge scores suggests that some may have lower levels of knowledge, which may warrant further study to improve knowledge in those students.

19.
Polymers (Basel) ; 16(11)2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38891516

ABSTRACT

Poly(dimethylsiloxane) (PDMS) coatings are considered to be environmentally friendly antifouling coatings. However, the presence of hydrophobic surfaces can enhance the adhesion rate of proteins, bacteria and microalgae, posing a challenge for biofouling removal. In this study, hydrophilic polymer chains were synthesised from methyl methacrylate (MMA), Poly(ethylene glycol) methyl ether methacrylate (PEG-MA) and 3-(trimethoxysilyl) propyl methacrylate (TPMA). The crosslinking reaction between TPMA and PDMS results in the formation of a silicone-based amphiphilic co-network with surface reconstruction properties. The hydrophilic and hydrophobic domains are covalently bonded by condensation reactions, while the hydrophilic polymers migrate under water to induce surface reconstruction and form hydrogen bonds with water molecules to form a dense hydrated layer. This design effectively mitigates the adhesion of proteins, bacteria, algae and other marine organisms to the coating. The antifouling performance of the coatings was evaluated by assessing their adhesion rates to proteins (BSA-FITC), bacteria (B. subtilis and P. ruthenica) and algae (P. tricornutum). The results show that the amphiphilic co-network coating (e.g., P-AM-15) exhibits excellent antifouling properties against protein, bacterial and microalgal fouling. Furthermore, an overall assessment of its antifouling performance and stability was conducted in the East China Sea from 16 May to 12 September 2023, which showed that this silicon-based amphiphilic co-network coating remained intact with almost no marine organisms adhering to it. This study provides a novel approach for the development of high-performance silicone-based antifouling coatings.

20.
Nutrients ; 16(11)2024 May 21.
Article in English | MEDLINE | ID: mdl-38892475

ABSTRACT

The association of hydration knowledge and health habits with hydration status and fluid intake is rarely examined. We sought to determine whether knowledge or physical health behaviors predict physiological hydration status and fluid intake. Ninety-six participants (59 female; 27 ± 10 year) completed the previously validated hydration survey. Participants then recorded total fluids consumed (TFC), collected urine, and tracked void frequency for 24 h. Hydration status was assessed via 24 h urine specific gravity (USG) and osmolality (Uosm). Health behaviors included self-reported physical activity, BMI, smoking, alcoholic drinking, and sleep status. TFC was significantly correlated with 24 h USG (r = -0.390; p < 0.001), Uosm (r = -0.486; p < 0.001), total urine volume (r = 0.675; p < 0.001), and void frequency (r = 0.518; p < 0.001). Hydration knowledge was not correlated with 24 h USG (r = 0.085; p = 0.420), Uosm (r = 0.087; p = 0.419), urine total volume (r = 0.019; p = 0.857), void frequency (r = 0.030; p = 0.771), or TFC (r = 0.027; p = 0.813). Hydration knowledge did not predict 24 h USG (LR+ = 1.10; LR- = 0.90), Uosm (LR+ = 0.81; LR- = 1.35), or TFC (LR+ = 1.00; LR- = 1.00). Health habits did not predict 24 h USG, Uosm, or TFC. In conclusion, self-reported 24 h diet and fluid log recording is comparable to hydration status verification via 24 h urine collection. Hydration knowledge and health habits are not related to, or predictive of, hydration status.


Subject(s)
Drinking , Health Behavior , Health Knowledge, Attitudes, Practice , Organism Hydration Status , Humans , Female , Male , Adult , Drinking/physiology , Organism Hydration Status/physiology , Young Adult , Specific Gravity , Dehydration/urine , Dehydration/physiopathology , Osmolar Concentration , Surveys and Questionnaires , Exercise/physiology , Water-Electrolyte Balance/physiology , Self Report
SELECTION OF CITATIONS
SEARCH DETAIL
...